Re: SIMS 3 - Invalid Base Game Code from Steam and Missing Free Sim Points
@613d66288369891a You're right that uninstalling is completely unnecessary here. The only problems are with the Store site and EA servers, not anything on your computer.
Can you download content from the Store? Even if you don't want to buy points right now, it's worth testing, and Riverview is free. Even if you can, the base game issue should still be addressed, but if you can't, that's all the more reason for support to help.
I would suggest contacting EA customer support, again, and asking that the base game be added back to your account because it's not appearing correctly. Support should be able to do this if you provide proof of ownership, which in this case should be as simple as posting a screenshot of your Steam library with your username and base game CD key showing. I'd suggest providing a screenshot of the Store page where your base game doesn't show up as well.
I would strongly recommend using live chat rather than email. If you don't see the option, try this link:
Make sure you're signed into an EA site (this one is fine) before clicking the link and that the location in the lower-right corner of the browser window is set to U.S. or U.K.